You could create a FIFO buffer or array(DB) of values for the 'on' state, aFIFO buffer or array (DB)of values for the 'off' state, and use a mid-value half-way in between to determine when the state changes.

When the state changes, look at the # of values in the array (you'll have to count them). Estimate the mid-point between the state changes, select the element represented by that mid-point, use that as your state 'value' for each state.

Do the math for the two values. You can set limits to generate warnings or alarms, and show the results.

You can also graph the signal if you get really creative.

Some thought will be required to prove a PLC (S7-1200) with at least 3 ms up to easily 30 ms is capable of computing the values from the presented signal.

It may be worthwhile to send the signal to two voltage thresholdfilters, and present twoanalog inputs to the PLC.

I have seen similar types of tasks done with a PLC, but it does take some creativity with the system to craft the right solution.

New question published by shabbu is split to a separate thread with the subject controlling hatcheries heater temperature.

Best regards
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